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Feb. 17, 1942.

c. C. PRINCE THERMOSTAT WAFER CONTROL FOR WOOD STOVES Filed March 17, 1941 f 15 i 22 /4 .t/

29 II a 20 f" lfiar/wfiv'lzce 'aafi mfz Patented Feb. 17, 1942 THERMOSTAT WAFER CONTROL FOR WOOD s'rovias Charles 0. Prince, Bostic, 0. Application March 17, 1941, Serial No. 383,864

2 Claims. (9;. 235-95) This invention relates to thermostat wafer controls for wood stoves and has foran object to. provide a simplified thermostat control in which the thermostat wafer will be disposed below and in front of the fire box of the stove so as not to be mfluenced by the fire, but rather to be influenced by the heat of the room and thus promote sensitivity of the device in controlling the damper. v

A further object is to provide means in adevice of this character for manually opening the damper to eliminatesmoke generated by smouldering wood while the thermostat has the damper cut off, thus permitting the smoke stack to draw the accumulated smoke up the stack before the stove lid is opened with the resultthat burstingof the smoke into the room when the lid is opened is positively prevented.

A further object's to provide in a device of this character a damper which lifts vertically in such a manner as to be'entirely free from any effect of the pull of the smoke stack, which effect in conventional dampers tends to shut such dampers off before the temperature demands, and to keep them shut off after the fallen temperature demands that they open.

A further object is to provide acounter-balancing weight detachably connected to the device of thehea wafer control, constructed in accordance with the invention. k

Figurezisa front elevation of the stove and thermostat wafer control.

Figure 3 is a fragmentary plan view, with parts broken away, showing the thermostat wafer control applied to the stove.

Figure 4 is a detail cross sectional view taken onthe line 4-4 of Figure 2.

Figure 5 is a detail longitudinal sectionallview taken on the line 55 of Figure 2.

Figure 6. is a perspective View of the counter balanced lever.

Figure 7 is a perspective view of the wire rod for connecting the weight to thelever and for securing the operating chain to the damper.

Referring now to the drawing in which like characters of reference designate similar parts in the various views, l0 designates a wood burning stove, which is supported upon legs II, and is provided in the top with a flue opening I2 and substantially rectangular shape, and curvedto for opening the damper when the thermostat wafer contracts and also to continuously hold the damper in the proper place by not permitting it to be shifted by changes in velocity of air currents in the room and around the. stove, or any change other, than the (temperature of the room, removal of the weight permittingof the fire to smoulder when so desired, even after the temperature of the room has dropped low enough for the thermostat to allow the weight to open the damper. I

A further object is to provide a device of this character which will be formed of a few strong, simple and durable parts, which will be inexpensive to manufacture, and which will not easily get out of order.

With the above and other objects in view, the invention consists of certain noveldetails of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing. from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming a part of this specification:

Figure 1 is a plan view, of a wood burning stove fit the contour of the cylindrical wall of the stove,

is provided with lugs l5 which are secured to the body of the stove by stove bolts IS. The casting is provided with'an opening H, which registers with the air supply opening l8 of the stove. The casting is offset outwardly to provide a substantially box-like rim having a flat front wall, best shown in Figure 4.

Afiue I9is provided with a semi-circular front wall 20, a flat back wall 2|, the back wall being disposed upon the front flat wall of the casting l4 and secured thereto by three bolts 22, best shown inFigure 2. The back wall is provided ,3 with an opening 23 which registers with the air,

. inlet opening l8 of the stove and air inlet opening ll of the casting.

A back plate 1 shaped to fit the inner surface of the wall of the stove in rear of the casting is secured to the stove and to the casting by the bolts I6. This plate is provided with an air inlet opening 6. This plate prevents the lining of the stove from puckering around the draft opening as a result of theintense heat generated when 1 the damper begins to open and while it remains v open.

A circular damper 24 is provided with a radially disposed handle 25. A retaining plate 9 is secured to the back wall 2| of the flue I9 bythe bolts22 to retain the damper in place. The

ter type equipped with a thermostatv retaining plate is provided with an air inlet opening 8. When the damper is in position to close the air inlet openings, above described, it is supported upon the bolts 22 and may be raised to any adjusted open position to increase the draft for maintaining a predetermined temperature in the room to be heated.

For operating the damper, a bracket 26 is secured at the upper end to the closed bottom 2'! of the flue l9, which bottom is formed integral with the casting I4. A lever 28 is pivoted between its ends on the bracket, as shown at 29 in Figure 2. The lower end of thebracketextends underneath a projecting end of the leverand a wafer thermostat 30 is secured to the bracket and under the projecting end of the lever.

A rod 3| is secured to the free end of the lever 28 and extends upwardly along the flue [9: to the open top of the flue. The rod is threaded and provided with a wing nut -32 for adjustably connecti-ng the rod to one end of a lever 33 which is pivoted, through a pivot pin 34, best shown'in Figure 3; to the back wall 2t of the flue F9. The lever extends across behind the flue between the wall 2! and the stove W, and projects atthe freeend beyond the flue t9, as' best shown in Figure 2. The lever is provided with agperforated out turned free end 35, best shown in-Figure 6, to receive a wire rod 35.

The wire rod 36, best shown in: Figure 7, is provided at one end with a ring 3'! to which is d'e-tachably connected the hook 31' of a. weight 38. The rod is provided with a V-shaped extension 39 which terminates inoppositely disposed gudgeons 4i) and 4!, the latter being pivotally engaged in the semi-circular front wall 2!!- ofthe flue 1-9 and theiormei being pivotally engaged in the flat rear wall of the flue to pivotally mount the wire rod 3Bthrough the flue. A chain 42 connects the inner endof the wire rod with the damper handle 25:

In operation, the air draft is taken in at the top ofthe stove through the flue l9 and enters the draft openings near the bottomof the stove so that the thermostat wafer 30 willnot be af-- fected by theheat of th'e'stove, but only by the room temperature; As the thermostat wafer 36 expands, the free endof the lever 28 will be pulled down and will pull down the rod' 3|, which in turn pulls down the end of the lever 33' connected thereto with resultant raising of the free end of the lever. This carries upward. the wire rod 36 so that the rod is rocked on the gudgeons 48- and 4| and the inner end of the rod is lowered with resultant lowering of the chain 42 to move the damper to adjustedclosedposition and partly or wholly shut off the draft. As the wafer contracts clue to a drop in temperature in the room'bel'ow a predetermined degree, the above movement of the parts just traced will be reversed due to gravitation of the weight 38' with resultant adjusted opening of the damper to partly open or fully open position to increase the draft.

For manually operating the damper, a chain 43 is connected to the chain 42 and at the upper end has one of its links engaged with. a pin- 44 7 2|. of the flue- Which projects from the back wall If]. The chain may be pulled up to lift the damper to open position and permit the smoke.

stack tov draw accumulated smoke from the stove before the stove lid, is. opened so that objectionable filling ofthe room with smoke when the" lid is lifted is-pcsitively prevented;

It will be pointed out that the counter-balancing weight 38 continuously holds the damper in proper place by not permitting it to be changed by velocity of air currents in the room around the stove. By detaching the weight from the rod 3!, the fire in the stove may be permitted to smoulder when desired, even after the temperature of the room has been dropped low enough for thethermostat to allow the weight to open the damper.

From the above description it is thought that the construction and operation of the invention will be fully understood without further explanation.

What is claimed is: 1., The combination with a Wood burning stove having a sheet metal wall provided with a draft opening nearthe bottom, of a down draft flue opening at the top at substantially the top of the stove and extending down along the wall of the stove to a point below the draft opening for conducting air from above the stove to said draft opening, means securing the flue to the wall of the stove, said flue being closed at the bottom, a thermostat wafer connected to the bottom of the flueand disposed below and in front of the fire box of the stove so as not to be directly influenced by the fire, a horizontally disposed lever pivoted between its ends below the flue and connected at one end to the wafer to be rocked thereby, a horizontally disposed lever pivoted to ably connected at the upper end to the second 35 namedlever and connected at the lower end to the first named lever, a wire rod pivoted in the upper end of the flue and connected to the second named lever, a weight detachably connected to one end of the wire rod, a chain connected to the other end of the Wire rod, a vertical damper controlling said draft opening connected to said chain, and a second chain connected to the first named chain tooperate the damper independently of the thermostat to eliminate smoke While the thermostathas the damper cut off, said weight opening the. damper when the thermostat wafer contracts and holding the damper in proper place to be unaffected by velocity of air currents or other causes than the temperature ofthe room to be heated, removal of the weight permitting of the fire to smoulder when so desired even after the temperatureof the room has dropped low enough for the thermostat to allow the weight. to open the damper. 55"

2. The combination with a wood burning stove having a sheet metal Wall provided with a draft openingnear-thebottom, of a casting on the Wall having a box-like portion extending over the draft opening and provided with a draft opening, a vertically movable damper on said box-like portion, a plate on the box-like portion in front of the damper having a draft opening holding the damper for vertical movement, a plate-adapted to engage the inner wall of the stove and having a draft. opening, means securing the casting. andv the last named plate together, said last named. plate preventing puckering of the lining of the stove at the draft opening, all of said draft openings being in alignment, a down draft flue extendingv upwardly along the wall of the stove on the exterior thereof and communicating at the bottom with said draft openings, the upper end of the flue being open and disposed at about the a plurality of screws securing the flue to the casting and forming stops against which the damper rests in closed position, the casting having an extension forming a bottom for said flue, a bracket depending from said bottom, a thermostat wafer connected to the bracket and disposed below and in front of the fire box of the stove so as not to be directly influenced by the fire, a horizontally disposed lever pivotally connected intermediate its ends on the bracket and connected at one end to the wafer to be rocked thereby, a horizontally disposed lever pivoted to the top of the flue and extending at both ends beyond the flue, a vertically disposed 10 thermostat wafer.

rod adjustably connected at one end to one of the levers and connected at the other end to the other lever, a Wire rod pivoted in the flue at the upper end thereof and connected to the second named lever, a weight detachably connected to the rod, a chain connected to the other end of the rod and connected to said damper, and a second chain operatively connected to the damper to operate the damper independently of the CHARLES C. PRINCE. 

